Answer:
12.65
Step-by-step explanation:
The formula for Pythagorean Theorem is 'a' squared + 'b' squared = 'c' squared. So let's call the base of this triangle, which is 3, 'a' and the length, which is the hypotenuses, 'c'. Now we need to plug it in. So, we square 3 and square 13. It's now (9+b=169). Solve the equation and you get b^2=160. So now we solve for the square root. And the answer is 12.6491106407 which you can round to 12.65
We have been given that Alexis received an 85, 89, and 92 on three tests and we are asked to find out the minimum grade Alexis can score on the fourth test in order to have an average of at least 90.
Let x be marks Alexis can score on the fourth test.
Since we know average is sum of all the numbers divided by number of items. Now we can set our given information in the average formula to get the minimum numbers Alexis can score on the fourth test.
Therefore, the minimum grade Alexis can score on the fourth test is 94, in order to have an average of at least 90.